Answer:
Step-by-step explanation:
The standard deviation is the square root of the variance, and the variance is found by using the mean. So we will do that first. I will use the population variance as opposed to the sample variance since our set of numbers is small.
The mean: 8 + 12 + 15 + 17 + 18 = 70 and divide that by 5 to get
and use this to find the variance in the formula:
it is a bit difficult to enter that formula in correctly, but here's how it works mathematically:

Squaring this ensures us that we don't end up with zero, which would be useless.
so
which means that the standard deviation is
s = 3.633
(If you do it with n-1 = 4 in the denominator of the variance, you get a standard deviation of 4.062)
The answer to this question would be "0.047 or B". This is because that is almost half of the test, and there's a lot of factors that vary. Such as the weight of the test, what answers she chose, etc. But it is B.
Answer: Base Ten Blocks, Number Line, Two Colored Counters
Answer:
x=2
Step-by-step explanation:
4x−7(2−x)=3x+2
4x+(−7)(2)+(−7)(−x)=3x+2(Distribute)
4x+−14+7x=3x+2
(4x+7x)+(−14)=3x+2(Combine Like Terms)
11x+−14=3x+2
11x−14=3x+2
Step 2: Subtract 3x from both sides.
11x−14−3x=3x+2−3x
8x−14=2
Step 3: Add 14 to both sides.
8x−14+14=2+14
8x=16
Step 4: Divide both sides by 8.
x=2
Answer: 11:7
Step-by-step explanation:
Number of green colored pencils=11
Number of blue colored pencils= 7
Number of red colored pencils= 3
Total number of colored pencils= 11+7+3= 21
Ratio of green colored pencils to blue colored pencils= 11:7